Science Forums 2

[CraigD]

Originally Posted by Gardamorg

If the plasma has a powerful magnetic field around it, how can it cut through anything?

You’d really need to ask a die-hard SWars fan for a committed defense of the “lightsaber is field-contained plasma” explanation, but I’ll give it my best shot.

Presumably the very high-temperature plasma in a lightsaber blade burns/melts anything it comes in contact with. Present day plasma cutters can not cut as deeply as, say, shown early in Episode 1, but they can cut nearly anything. Plasma cutters don’t use any sort of field to contain their plasma, they’re just held close to what they should cut, and shoot the plasma there with a gas jet.

Why light sabers don’t knock any vaguely magnetic thing they approach out of the way of their hot, glowing, cutting part is a question for a fan expert. Scientifically, it doesn’t make sense.

Of course, lightsaber blades are never shown in the movies cutting other lightsaber blades, presumably due to the interaction of their plasma-containing fields. Presumably this means that other magnetic “shielding” can block a lightsaber. Perhaps the “ray-shielded” trash masher in Episode 4 is not only blaster-proof, but lightsaber-proof, too.

Of course, lightsaber blades can defect blaster bolts, presumably because they’re charged plasma similar to the kind contained in a lightsaber blade.

Why the designers of that worthless white stormtrooper armor didn’t think to build in "ray-shielding", making the stuffblaster and light-saber proof, I’ll leave to a true fan expert.

Another mystery is why lightsabers never seem to start fires. One would think that the slightest touch of them to flammable cloths, furnature, fuel, etc. would set it all ablaze, but except of an occasional ember or burn mark when someone gets a limb lopped off, you never see much ignition. Perhaps they have built-in fire extinguisher systems?

Ultimately, I think, it’s best not to take lightsabers too seriously. They are, after all, make-believe. Lucas wasn’t really trying for any scientific realism in Episode 4, just a cool-looking special effect that showed Jedi to be dashing, swash-buckling, dangerous beings with exotic, “elegant”, deadly weapons that lesser beings lacked.